Generally, a capacitor-input type rectifier circuit is widely used as a switching power supply that is used as a power supply for an electronic device. An input current of a pulse type is generated by such a capacitor. Since the pulse-type input current is concurrently generated at each input of an electronic, information, and communication device, the pulse-type input current is added in phase on a distribution line, which results in a harmonic distortion of a power system and the degradation of power factor of a commercial power supply.
To address these problems, research and development is now actively made on a control circuit of a boost-type power factor correction (PFC) having a power factor correction function.
FIG. 1 is a diagram illustrating a conventional power supply device of a boost converter type.
With reference to FIG. 1, a conventional power supply device 1 has a configuration in which an input power source is connected to both ends of a rectifier 2, an inductor 3 is connected between the rectifier 2 and a switching element 4 as an energy storage element, and a diode is connected between the switching element 4 and a capacitor.
The above power supply device 1 amplifies a voltage at an input end to a predetermined ratio to output the amplified voltage to an output terminal 5.
When high voltage such as line-to-line voltage in a three-phase system is applied to the power supply device 1, extremely high voltage is provided to the output terminal 5. Accordingly, voltage stress on a semiconductor device at the output terminal is increased, and thus an insulated gate bipolar transistor (IGBT) element rather than a field effect transistor (FET) element is used as a switching element. Thus, there is a disadvantage in that a low switching frequency should be used according to the use of the IGBT element. Furthermore, there is a design limitation of a power supply device in that a size of a passive element is increased, costs for manufacturing are increased, and so on.